Article 1, Section 8, Clause 10
Document 12
William Rawle, A View of the Constitution of the United States 106--9 1829 (2d ed.)
The regulation of foreign commerce appertains to congress alone, and the punishment of offences committed on the high seas is an unavoidable incident to this power: as soon as the Constitution was adopted, the power of the states in this respect was at an end. But the principle of this exclusive jurisdiction might perhaps be further extended. After the territorial boundaries of a nation are left, the sea becomes the common property of all nations, and the rights and privileges relative thereto being regulated by the law of nations and treaties, properly belong to the national jurisdiction, and would be inconveniently retained by the states which, in this respect, form only parts of the nation.
It does not seem to have been necessary to define the crime of piracy. There is no act on which the universal sense of nations has been so fully and distinctly expressed, as there is no act which is so universally punished. The pirate is the enemy of all nations, and all nations are the enemy of the pirate.
Felony is a term derived from the common law of England, and when committed on the high seas, amounts to piracy. The power to define either may have been introduced to authorize congress to qualify and reduce the acts which should amount to either. It is coupled with the power to punish, and this power extends not merely to citizens of the United States, but to all others except the citizens or subjects of a foreign state sailing under its flag and committing acts which amount to piracy; but general piracy committed by persons on board of a vessel, acting in defiance of all law, and acknowledging obedience to no government, are punishable in our courts, and in the courts of all nations.
By the high seas we are to understand not only the ocean out of sight of land, but waters on the sea coast beyond the boundaries of low water mark, although in a roadstead or bay, within the jurisdiction or limits of one of the states or of a foreign government.
A power to define and to punish offences against the law of nations is contained in the same paragraph, but it is doubtful whether the power to punish ought to be considered as an exclusive one. The law of nations forms a part of the common law of every civilized country; violations of it may be committed as well on land as at sea, and while the jurisdiction of the separate states is admitted to be withdrawn from them in regard to acts committed on the sea, it does not seem to follow that it is superseded as to those on shore.
Such acts may be of various kinds, and although the most prominent subjects under this head are those which relate to the persons and privileges of ambassadors, yet in many other particulars, infringements of the law of nations may be proper subjects of state jurisdiction. But even if an outrage were committed on a diplomatic character, and he preferred the redress to be obtained from a state court to that afforded by the courts of the United States, it is not perceived that this clause would prohibit him from so doing; yet whether the power is exclusive or not, on which some further remarks will be made, the power to define and to punish this class of offences is with great propriety given to congress. The United States being alone responsible to foreign nations for all that affects their mutual intercourse, and tends to promote the general relations of good order and just demeanour, it rests with them alone to declare what shall constitute such crimes, and to prescribe suitable punishments.
When such laws are made, they become binding rules of decision as well on the state courts as on the courts of the United States; but if cases arise for which no such statutory provision has been made, both these descriptions of courts are thrown upon those general principles, which being enforced by other nations, those nations have a right to require us to apply and enforce in their favour, or for the benefit of their citizens and subjects.
The Founders' Constitution
Volume 3, Article 1, Section 8, Clause 10, Document 12
http://press-pubs.uchicago.edu/founders/documents/a1_8_10s12.html
The University of Chicago Press
Rawle, William. A View of the Constitution of the United States of America. 2d ed. Philadelphia, 1829. Reprint. New York: Da Capo Press, 1970.